I joined Lightbend a little more than four years ago, and soon I began to visit customers and train them to build reactive architectures. I heard the same questions over and over again, and in trying to explain the principles, I learned much of what this book is about. But I wouldn’t have written the book if it weren’t for my friend Raymond Roestenburg.
The opportunity to write this edition of this book came to me by accident. I was working with Ray, and one day, he told me that he had written the previous edition. It was a bit outdated by then, and he thought it would make sense to have the next edition deal with the conversion from Akka Classic to Akka Typed. Writing a book is a lot of work, and he didn’t have the time. I did, and I didn’t lack motivation. I got in touch with Manning, and we made a plan. And here we are.
Since the first edition of this book, Akka has changed a lot, not only from untyped to typed actors but also to include some other abstractions—storing the state of actors with Akka Persistence, evenly distributing actors with Akka Sharding, creating views from an actor’s history with Akka Projections, and more. Some of these abstractions were already there but were not used as often, and others are brand new.